Hongling Ye^*, Zonghan Li, Nan Wei, Pengfei Su, Yunkang Sui

CMES-Computer Modeling in Engineering & Sciences, Vol.128, No.1, pp. 297-314, 2021, DOI:10.32604/cmes.2021.016133

Abstract Fatigue failure is a common failure mode under the action of cyclic loads in engineering applications, which often occurs with no obvious signal. The maximum structural stress is far below the allowable stress when the structures are damaged. Aiming at the lightweight structure, fatigue topology optimization design is investigated to avoid the occurrence of fatigue failure in the structural conceptual design beforehand. Firstly, the fatigue life is expressed by topology variables and the fatigue life filter function. The continuum fatigue optimization model is established with the independent continuous mapping (ICM) method. Secondly, fatigue life constraints are transformed to distortion energy… More >

Daojun Han^1,2,3, Jinyu Chen^3,4, Lei Zhang^1,2,3,*, Yatian Shen^1,2,3, Yihua Gao^3,5, Xueheng Wang^3,6

CMES-Computer Modeling in Engineering & Sciences, Vol.128, No.1, pp. 223-245, 2021, DOI:10.32604/cmes.2021.016000

Abstract As one of the most valuable technologies, blockchains have received extensive attention from researchers and industry circles and are widely applied in various scenarios. However, data on a blockchain cannot be deleted. As a result, it is impossible to clean invalid and sensitive data and correct erroneous data. This, to a certain extent, hinders the application of blockchains in supply chains and Internet of Things. To address this problem, this study presents a deletable and modifiable blockchain scheme (DMBlockChain) based on record verification trees (RVTrees) and the multisignature scheme. (1) In this scheme, an RVTree structure is designed and added… More >

Zihao Zong, Tielin Shi, Qi Xia^*

CMES-Computer Modeling in Engineering & Sciences, Vol.128, No.1, pp. 283-295, 2021, DOI:10.32604/cmes.2021.015975

Abstract A parameter-free approach is proposed to determine the Lagrange multiplier for the constraint of material volume in the level set method. It is inspired by the procedure of determining the threshold of sensitivity number in the BESO method. It first computes the difference between the volume of current design and the upper bound of volume. Then, the Lagrange multiplier is regarded as the threshold of sensitivity number to remove the redundant material. Numerical examples proved that this approach is effective to constrain the volume. More importantly, there is no parameter in the proposed approach, which makes it convenient to use.… More >

Yu Han¹, Tiantian Ji¹, Zhongru Wang^1,2,*, Hao Liu^3,*, Hai Jiang⁴, Wendi Wang¹, Xiang Cui⁵

CMES-Computer Modeling in Engineering & Sciences, Vol.128, No.1, pp. 247-267, 2021, DOI:10.32604/cmes.2021.015809

Abstract A smart contract honeypot is a special type of smart contract. This type of contract seems to have obvious vulnerabilities in contract design. If a user transfers a certain amount of funds to the contract, then the user can withdraw the funds in the contract. However, once users try to take advantage of this seemingly obvious vulnerability, they will fall into a real trap. Consequently, the user’s investment in the contract cannot be retrieved. The honeypot induces other accounts to launch funds, which seriously threatens the security of property on the blockchain. Detection methods for honeypots are available. However, studying… More >

Weiping Luo^1,2, Dajun Yuan^1,2, Dalong Jin^1,2,*, Ping Lu^1,2, Jian Chen³

CMES-Computer Modeling in Engineering & Sciences, Vol.128, No.1, pp. 109-127, 2021, DOI:10.32604/cmes.2021.015683

Abstract The control of slurry pressure aiming to be consistent with the external water and earth pressure during shield tunnelling has great significance for face stability, especially in urban areas or underwater where the surrounding environment is very sensitive to the fluctuation of slurry pressure. In this study, an optimal control method for slurry pressure during shield tunnelling is developed, which is composed of an identifier and a controller. The established identifier based on the random forest (RF) can describe the complex non-linear relationship between slurry pressure and its influencing factors. The proposed controller based on particle swarm optimization (PSO) can… More >

Fouad A. Abolaban^*

CMES-Computer Modeling in Engineering & Sciences, Vol.128, No.1, pp. 183-201, 2021, DOI:10.32604/cmes.2021.015472

Abstract Various epidemics have occurred throughout history, which has led to the investigation and understanding of their transmission dynamics. As a result, non-local operators are used for mathematical modeling in this study. Therefore, this research focuses on developing a dysentery diarrhea model with the use of a fractional operator using a one-parameter Mittag–Leffler kernel. The model consists of three classes of the human population, whereas the fourth one belongs to the pathogen population. The model carefully deals with the dimensional homogeneity among the parameters and the fractional operator. In addition, the model was validated by fitting the actual number of dysentery… More >

Gaoge Zhao, Jianzhong Chen, Yong Lv^*, Xiaoyu Zhang, Li Huang

CMES-Computer Modeling in Engineering & Sciences, Vol.128, No.1, pp. 339-357, 2021, DOI:10.32604/cmes.2021.015388

Abstract The influence of different nanoparticle sizes on the elastic modulus and the fatigue properties of epoxy/SiO₂ nanocomposite is studied in this paper. Here, the cross-linked epoxy resins formed by the combination of DGEBA and 1,3-phenylenediamine are used as the matrix phase, and spherical SiO₂ particles are used as the reinforcement phase. In order to simulate the elastic modulus and long-term performance of the composite material at room temperature, the simulated temperature is set to 298 K and the mass fraction of SiO₂ particles is set to 28.9%. The applied strain rate is 10⁹/s during the simulation of the elastic modulus.… More >

Shufang Song^1,*, Ruyang He¹, Zhaoyin Shi¹, Weiya Zhang²

CMES-Computer Modeling in Engineering & Sciences, Vol.128, No.1, pp. 65-85, 2021, DOI:10.32604/cmes.2021.015378

Abstract The variable importance measure (VIM) can be implemented to rank or select important variables, which can effectively reduce the variable dimension and shorten the computational time. Random forest (RF) is an ensemble learning method by constructing multiple decision trees. In order to improve the prediction accuracy of random forest, advanced random forest is presented by using Kriging models as the models of leaf nodes in all the decision trees. Referring to the Mean Decrease Accuracy (MDA) index based on Out-of-Bag (OOB) data, the single variable, group variables and correlated variables importance measures are proposed to establish a complete VIM system… More >

Yunliang Huo¹, Ji Xiong^1,*, Zhixing Guo¹, Qianbing You¹, Yi Peng²

CMES-Computer Modeling in Engineering & Sciences, Vol.128, No.1, pp. 359-379, 2021, DOI:10.32604/cmes.2021.015314

Abstract Cloud manufacturing is a new manufacturing model with crowd-sourcing characteristics, where a cloud alliance composed of multiple enterprises, completes tasks that a single enterprise cannot accomplish by itself. However, compared with heterogeneous cloud tasks, there are relatively few studies on cloud alliance formation for homogeneous tasks. To bridge this gap, a novel method is presented in this paper. First, a homogeneous cloud task distribution model under cloud environment was constructed, where services description, selection and combination were modeled. An improved leapfrog algorithm for cloud task distribution (ILA-CTD) was designed to solve the proposed model. Different from the current alternatives, the… More >

İlyas Kacar^*

CMES-Computer Modeling in Engineering & Sciences, Vol.128, No.1, pp. 87-108, 2021, DOI:10.32604/cmes.2021.015227

Abstract Locking nuts are widely used in industry and any defects from their manufacturing may cause loosening of the connection during their service life. In this study, simulations of the folding process of a nut’s flange made from AISI 1040 steel are performed. Besides the bilinear isotropic hardening rule, Chaboche’s nonlinear kinematic hardening rule is employed with associated flow rule and Hill48 yield criterion to set a plasticity model. The bilinear isotropic hardening rule’s parameters are determined by means of a monotonic tensile test. The Chaboche’s parameters are determined by using a low cycle tension/compression test by applying curve fitting methods… More >